Power conversion apparatus and charging apparatus

Abstract

A power conversion apparatus includes an AC-DC conversion circuit, a power controller, and a circulating current controller. The power controller is configured to control the AC-DC conversion circuit to convert a received alternating current into a first direct current and output the first direct current. The circulating current controller is configured to send a synchronization signal to another power conversion apparatus through a controller area network (CAN) bus. The synchronization signal is used to synchronize a carrier of the another power conversion apparatus with a carrier of the power conversion apparatus.

What is claimed is: 
     
         1 . A power conversion apparatus, comprising:
 an alternating current-direct current (AC-DC) conversion circuit;   a power controller connected to the AC-DC conversion circuit, and the power controller is configured to:
 control the AC-DC conversion circuit to receive an alternating current, 
 convert the alternating current into a first direct current, and 
 output the first direct current; and 
   a circulating current controller configured to send a synchronization signal to another power conversion apparatus through a controller area network (CAN) bus and the synchronization signal is used to synchronize a carrier of the another power conversion apparatus with a carrier of the power conversion apparatus.   
     
     
         2 . The power conversion apparatus according to  claim 1 , wherein the circulating current controller comprises:
 a first primary timer configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the power conversion apparatus to be synchronized with a target carrier period, and the target carrier period is synchronized with a period of the carrier of the another power conversion apparatus.   
     
     
         3 . The power conversion apparatus according to  claim 2 , wherein the circulating current controller further comprises:
 a first secondary timer connected to the first primary timer, and the first primary timer is further configured to:   when a count value of the first primary timer is a period value of the target carrier period, send a first trigger signal to the first secondary timer, wherein the first trigger signal indicates to reset a count value of the first secondary timer, so that the first primary timer is synchronized with the first secondary timer.   
     
     
         4 . The power conversion apparatus according to  claim 2 , wherein the circulating current controller further comprises:
 a synchronization timer connected to the first primary timer and the another power conversion apparatus, and the synchronization timer is configured to:   when a count value of the synchronization timer is a first period value, send the synchronization signal to the first primary timer and the another power conversion apparatus.   
     
     
         5 . The power conversion apparatus according to  claim 1 , further comprising:
 a circulating current detection circuit, and the AC-DC conversion circuit comprises a plurality of switches, the circulating current detection circuit is connected to an input end of the AC-DC conversion circuit and the circulating current controller, and the circulating current detection circuit is configured to:   detect a circulating current value at the input end of the AC-DC conversion circuit, and   transmit the circulating current value to the circulating current controller, and the circulating current controller is further configured to:   receive a first modulated wave from the power controller, and   adjust the first modulated wave based on the circulating current value, to obtain a second modulated wave, wherein the second modulated wave is used to determine a drive signal and the drive signal is used to control turn-on time of the plurality of switches.   
     
     
         6 . The power conversion apparatus according to  claim 5 , wherein the circulating current controller is further configured to:
 determine a circulating current deviation based on the circulating current value and a preset circulating current threshold;   perform operation adjustment on the circulating current deviation, to obtain a first compensation amount; and   perform superposition processing on the first compensation amount and the first modulated wave, to obtain the second modulated wave.   
     
     
         7 . The power conversion apparatus according to  claim 5 , wherein the circulating current controller is further configured to:
 send the second modulated wave to the power controller; and the power controller is further configured to:   determine the drive signal based on the second modulated wave and the carrier of the power conversion apparatus.   
     
     
         8 . A power conversion apparatus, comprising:
 an alternating current-direct current (AC-DC) conversion circuit;   a power controller connected to the AC-DC conversion circuit, and the power controller is configured to control the AC-DC conversion circuit to receive an alternating current, convert the alternating current into a first direct current, and output the first direct current; and   a circulating current controller configured to receive a synchronization signal from another power conversion apparatus through a controller area network (CAN) bus and the synchronization signal is used to synchronize a carrier of the power conversion apparatus with a carrier of the another power conversion apparatus.   
     
     
         9 . The power conversion apparatus according to  claim 8 , wherein the circulating current controller comprises:
 a second primary timer configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the power conversion apparatus to be synchronized with a target carrier period, and the target carrier period is synchronized with a period of the carrier of the another power conversion apparatus.   
     
     
         10 . The power conversion apparatus according to  claim 9 , wherein the circulating current controller further comprises:
 a second secondary timer connected to the second primary timer, and the second primary timer is further configured to:   when a count value of the second primary timer is a period value of the target carrier period, send a second trigger signal to the second secondary timer, and the second trigger signal indicates to reset a count value of the second secondary timer, so that the second primary timer is synchronized with the second secondary timer.   
     
     
         11 . The power conversion apparatus according to  claim 9 , further comprising:
 a circulating current detection circuit, the AC-DC conversion circuit comprises a plurality of switches, the circulating current detection circuit is connected to an input end of the AC-DC conversion circuit and the circulating current controller, and the circulating current detection circuit is configured to:   detect a circulating current value at the input end of the AC-DC conversion circuit, and   transmit the circulating current value to the circulating current controller; and the circulating current controller is further configured to:   receive a first modulated wave from the power controller and adjust the first modulated wave based on the circulating current value, to obtain a second modulated wave, the second modulated wave is used to determine a drive signal, and the drive signal is used to control turn-on time of the plurality of switches.   
     
     
         12 . The power conversion apparatus according to  claim 11 , wherein the circulating current controller is further configured to:
 determine a circulating current deviation based on the circulating current value and a preset circulating current threshold;   perform operation adjustment on the circulating current deviation, to obtain a first compensation amount; and   perform superposition processing on the first compensation amount and the first modulated wave, to obtain the second modulated wave.   
     
     
         13 . The power conversion apparatus according to  claim 11 , wherein the circulating current controller is further configured to:
 send the second modulated wave to the power controller; and the power controller is further configured to:   determine the drive signal based on the second modulated wave and the carrier of the power conversion apparatus.   
     
     
         14 . A charging apparatus, comprising a plurality of power conversion apparatuses and a direct current bus, wherein the plurality of power conversion apparatuses are disposed in parallel, and each of the plurality of power conversion apparatuses comprises:
 an alternating current-direct current (AC-DC) conversion circuit;   a power controller connected to the AC-DC conversion circuit, and the power controller is configured to:
 control the AC-DC conversion circuit to receive an alternating current, 
 convert the alternating current into a first direct current, and 
 output the first direct current through the direct current bus; and 
   a circulating current controller;   the plurality of power conversion apparatuses comprise a primary power conversion apparatus and at least one secondary power conversion apparatus, a circulating current controller of the primary power conversion apparatus is a primary circulating current controller, and a circulating current controller of the secondary power conversion apparatus is a secondary circulating current controller; and the primary circulating current controller is configured to:   send a synchronization signal to the secondary circulating current controller through a controller area network (CAN) bus, and the synchronization signal is used to synchronize a carrier of the secondary power conversion apparatus with a carrier of the primary power conversion apparatus.   
     
     
         15 . The charging apparatus according to  claim 14 , wherein the primary circulating current controller comprises a first primary timer, and the secondary circulating current controller comprises a second primary timer;
 the first primary timer is configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the primary power conversion apparatus to be synchronized with a target carrier period; and   the second primary timer is configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the secondary power conversion apparatus to be synchronized with the target carrier period.   
     
     
         16 . The charging apparatus according to  claim 15 , wherein the primary circulating current controller further comprises a first secondary timer, and the secondary circulating current controller further comprises a second secondary timer;
 the first secondary timer is connected to the first primary timer, and the second secondary timer is connected to the second primary timer;   the first primary timer is further configured to:   when a count value of the first primary timer is a period value of the target carrier period, send a first trigger signal to the first secondary timer, and the first trigger signal indicates to reset a count value of the first secondary timer, so that the first primary timer is synchronized with the first secondary timer; and   the second primary timer is further configured to:   when a count value of the second primary timer is the period value of the target carrier period, send a second trigger signal to the second secondary timer, and the second trigger signal indicates to reset a count value of the second secondary timer, so that the second primary timer is synchronized with the second secondary timer.   
     
     
         17 . The charging apparatus according to  claim 15 , wherein the primary circulating current controller further comprises a synchronization timer, and the synchronization timer is connected to the first primary timer and the second primary timer; and
 the synchronization timer is configured to:   when a count value of the synchronization timer is a first period value, send the synchronization signal to the first primary timer and the second primary timer.   
     
     
         18 . The charging apparatus according to  claim 14 , wherein the power conversion apparatus further comprises a circulating current detection circuit, the AC-DC conversion circuit comprises a plurality of switches, the circulating current detection circuit is connected to an input end of the AC-DC conversion circuit and the circulating current controller, and the circulating current detection circuit is configured to:
 detect a circulating current value at the input end of the AC-DC conversion circuit and   transmit the circulating current value to the circulating current controller; and the circulating current controller is configured to:   receive a first modulated wave from the power controller and adjust the first modulated wave based on the circulating current value, to obtain a second modulated wave, and the second modulated wave is used to determine a drive signal, and the drive signal is used to control turn-on time of the plurality of switches.   
     
     
         19 . The charging apparatus according to  claim 18 , wherein the circulating current controller is further configured to:
 determine a circulating current deviation based on the circulating current value and a preset circulating current threshold;   perform operation adjustment on the circulating current deviation, to obtain a first compensation amount; and   perform superposition processing on the first compensation amount and the first modulated wave, to obtain the second modulated wave.   
     
     
         20 . The charging apparatus according to  claim 18 , wherein the circulating current controller is further configured to:
 send the second modulated wave to the power controller; and the power controller is further configured to:   determine the drive signal based on the second modulated wave and the carrier of the power conversion apparatus.